[PATCH 08/19] thunderbolt: Allocate ring HopID before requesting the ring interrupt

Sven Peter sven at kernel.org
Sun Aug 30 13:19:26 PDT 2026


The Apple NHI has one interrupt per ring and request_ring_irq picks it
based on ring->hop which is still -1 at this point for rings allocated
with an automatic HopID. Allocate the HopID first and release it again
if the interrupt request fails.

Signed-off-by: Sven Peter <sven at kernel.org>
---
 drivers/thunderbolt/nhi.c | 23 ++++++++++++++++-------
 1 file changed, 16 insertions(+), 7 deletions(-)

diff --git a/drivers/thunderbolt/nhi.c b/drivers/thunderbolt/nhi.c
index 5809809f64d4..6a97dcd57deb 100644
--- a/drivers/thunderbolt/nhi.c
+++ b/drivers/thunderbolt/nhi.c
@@ -534,6 +534,16 @@ static int nhi_alloc_hop(struct tb_nhi *nhi, struct tb_ring *ring)
 	return ret;
 }
 
+static void nhi_free_hop(struct tb_nhi *nhi, struct tb_ring *ring)
+{
+	guard(spinlock_irq)(&nhi->lock);
+
+	if (ring->is_tx)
+		nhi->tx_rings[ring->hop] = NULL;
+	else
+		nhi->rx_rings[ring->hop] = NULL;
+}
+
 static struct tb_ring *tb_ring_alloc(struct tb_nhi *nhi, u32 hop, int size,
 				     bool transmit, unsigned int flags,
 				     int e2e_tx_hop, u16 sof_mask, u16 eof_mask,
@@ -581,19 +591,18 @@ static struct tb_ring *tb_ring_alloc(struct tb_nhi *nhi, u32 hop, int size,
 	if (!ring->descriptors)
 		goto err_free_ring;
 
+	if (nhi_alloc_hop(nhi, ring))
+		goto err_free_descs;
+
 	if (!(flags & RING_FLAG_NO_INTERRUPT) && nhi->ops->request_ring_irq) {
 		if (nhi->ops->request_ring_irq(ring, flags & RING_FLAG_NO_SUSPEND))
-			goto err_free_descs;
+			goto err_free_hop;
 	}
 
-	if (nhi_alloc_hop(nhi, ring))
-		goto err_release_msix;
-
 	return ring;
 
-err_release_msix:
-	if (nhi->ops->release_ring_irq)
-		nhi->ops->release_ring_irq(ring);
+err_free_hop:
+	nhi_free_hop(nhi, ring);
 err_free_descs:
 	dma_free_coherent(ring->nhi->dev,
 			  ring->size * sizeof(*ring->descriptors),

-- 
2.55.0





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